A small amount of mercury is released from dental amalgam restorations and may be absorbed in the human body. Although the restorations are believed not to be a health hazard to the majority of patients, some concern remains because of the toxicity of mercury. The goal of this research is to gain a scientific understanding of the processes involved and to use the knowledge to minimize the release. The study will be performed in the laboratory using a simulated oral environment. The objective is to measure the mercury dissolution and evaporation rates for both resting conditions and those simulating abrasion by chewing. The rates will be determined for representative dental amalgams as well as samples of the mercury-containing part of the amalgam structure. The effects of variations in the temperature and acidity of the oral environment will be evaluated. Kinetics of the formation of an oxide film, which is the main barrier against mercury dissolution from dental amalgam, will be studied. The experimental techniques will include solution analysis by Atomic Absorption Spectrophotometry, and electrochemical measurements. The results of the study will show at what rate the mercury release can occur, and which part of the process controls it. They will serve as a basis for a selection of measures to lower the release.